<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>规定字符间距</title>
</head>

<body>
    <style>
        h1 {
            letter-spacing: 3px;
        }

        h2 {
            letter-spacing: -3px;
        }
    </style>
    <h1>This is heading 1</h1>
    <h2>This is heading 2</h2>
</body>

</html>